When you write several JUnit classes, it becomes uncomfortable to run them individually. You can run all the Xtend tests in a package by right-clicking on the corresponding package in the xtend-gen folder and select Run As | JUnit Test.

If you need more control over the tests that must be run or you want to group some tests, you can write a JUnit Test Suite. For example, you can write a suite for tests which are not related to generation as shown in the following Java class:

import org.junit.runner.RunWith;
import org.junit.runners.Suite;

@RunWith(Suite.class)
@Suite.SuiteClasses({
    EntitiesParsingTest.class,
    EntitiesFormatterTest.class,
    EntitiesValidatorTest.class
})
public class EntitiesNotGeneratorRelatedTests {
}

You can run such suite as a standard JUnit test, and it will run all the test methods in all the test classes specified in the test suite.